The present invention relates to a bone plating system, instrumentation and method of use used in the fixation of fractures of long bones such as the femur, tibia, humerus and radius, including periarticular fractures. More specifically, the present invention encompasses an aiming block fixation system that aids in the location of bone screws and drilling of pilot holes for the placement and intraoperative adjustment and fixation of the plate to the fractured bone.
Typical fixation of a fracture of a long bone with a bone plate requires making an incision in the tissue, reducing the fracture, placing a bone plate on the fractured bone, and securing the bone plate to the bone with fixation elements such as screws. The bone plate immobilizes the fracture and keeps the bone in a correct position so as to allow the fracture to heal.
Typically, bone plates have a bone-contacting side and a side facing away from the bone with a plurality of holes or apertures extending between the two surfaces. These holes or apertures may be either threaded (for fixing the plate to the bone with locking screws) or non-threaded (for fixing the plate to the bone with regular screws) and may be circular or oblong in shape.
Such threaded screws are driven into the bone tissue after so-called pre-drilled or pilot-drilled holes have been generated in the bone tissue. These pre-drilled holes allow for a reliable screwing procedure whereby the risk of further destroying the bone with the screw is significantly reduced.
In order to facilitate the drilling of these pre-drilled holes there are known so-called aiming or targeting devices, which work like a drilling jig. Thereby, an aiming or targeting device is detachably fixed to the metal bone plate in a precise position.
One such bone plate is shown in U.S. Pat. No. 6,623,486 in which the plate has a head portion for placement adjacent the metaphysis of the bone and a shaft portion for placement against the diaphysis of the bone. The plate includes both locking (threaded) holes and non-locking holes. The locking holes are adapted to receive bone screws with threaded heads or proximal areas which engage the threads in the locking holes to thereby lock the screw to the plate. Bone screws without threaded heads can be then inserted into the non-locking holes or into the oblong holes which oblong holes permit the screws to be oriented at various angles.
Some types of bone plates, however, do not include threaded holes in a location that would accommodate the use of aiming or targeting devices. There thus exists a need for a system that will align a surgical tool (e.g., drill bit) with a hole of a bone plate in which the holes can be non-threaded. The present invention addresses this problem and others by providing an aiming block which has bores for aligning surgical tools, whose arrangement matches or corresponds to the arrangement of holes of a particular bone plate type. Given the lack of threaded holes in this particular bone plate type, the present invention provides a fixation system including a locking element which engages a surface surrounding a hole in the bone plate, whereby the aiming block is fixed to the bone plate.